1. Field of the invention:
The present invention relates to an automatic musical tone generating apparatus for successively reading out at a predetermined tempo plural sets of pitch information preliminarily stored and automatically generating musical tones on the basis of the read-out pitch information, and more specifically to an automatic musical tone generating apparatus so improved as to impart the slur effect (slide effect) of smooth shift from a certain pitch to a next pitch to the generated tones.
2. Description of the prior art:
As the prior art, Japanese Patent Laid-open No. Sho 58-211787 disclosed an electronic musical instrument which is capable of realizing the so-called slur effect, slide effect and portamento effect, when a new key is depressed on the keyboard, by converting pitch information representing the key depressed immediately previously into pitch information gradually shifting toward the pitch information representing the key newly depressed, and outputting the converted pitch information to the tone generating circuit so as to obtain a musical tone of a pitch smoothly shifting from the key depressed immediately previously toward the key newly depressed.
However, in case of the above-mentioned conventional musical apparatus wherein pitch is shifted, after a new key is depressed, from the pitch of the musical tone whose generation has already been finished to the pitch corresponding to the key newly depressed, the effect is different from the slur effect in its original sense which should shift pitch smoothly toward the future and the generated musical tones are unnatural. Therefore, the performer of the above-mentioned electronic musical instrument must efface the unnaturality by depressing, when a note with the slur sign appears on a score, the key corresponding to the note earlier by one note length than the timing specified for the note on the score. However, such performance is possible only for extremely skilled persons and the conventional musical apparatus poses a problem that it cannot be operated well by ordinary persons. For this reason, it has hithereto been desired to obtain a musical apparatus which can provide the natural slur effect in a simple procedure.